Hitachi Jimpu

The early development of aircraft in Japan was fully dependent on engines from abroad, although many of these designs were license built by Japanese companies. Gasuden was no exception, building Le Rhone rotaries in the early 1920s.{{sfn|Sanger|2002|page=155}} However, by 1926, the company had gained enough experience to develop its own first engine. Taking inspiration from the Armstrong Siddeley Mongoose, the company developed a seven-cylinder star-shaped radial made of alloy and using an integral impellor-based carburettor.{{sfn|Suzuki|et al|2008|page=2405}} The prototype was first run in 1927 and was the first indigenous design to achieve production in Japan.{{sfn|Gunston|2006|page=124}}

The resulting engine was a single row radial with seven cylinders of bore {{convert|115|mm|in|abbr=on}} and stroke {{convert|120|mm|in|abbr=on}}.{{sfn|Ursinus|1941|page=195}} Running on 80 Octane fuel, the engine was rated at sea level at {{convert|150|hp|kW|0|abbr=on}}.{{sfn|Wilkinson|1945|page=349}} The engine had no compressor, although some later models were fitted with a single speed mechanical supercharger to boost performance.{{sfn|Suzuki|et al|2008|page=2405}}

Initially, the engine was first known as the {{nihongo|divine wind|神風|Kamikaze}}, but was later better known as the {{nihongo|encampment wind|陣 風|Jimpu}} as the range of engines produced by the company increased. Production ran from 1928 to 1944. {{sfn|Suzuki|et al|2008|page=2404}} Large numbers were delivered, primarily for training and other light aircraft. Amongst the more numerous were the Yokosuka K2Y2 Type 3, a derivative of the Avro 504N which was produced from 1929 to 1940, and the Yokosuka K4Y1 seaplane produced between 1933 and 1940, mainly by Watanabe.{{sfn|Jackson|Jackson|2000|page=119}}{{sfn|Francillon|1970|page=494}} In May 1939, Hitachi acquired Tokyo Gas and Electric Company, merging the aeronautical part of the business with Hitachi Aircraft.{{sfn|Iguchi|2003|pages=176–177}} The engine was rebranded Hitachi. Production totalled between 8,300 and 12,500 units.{{sfn|Suzuki|et al|2008|page=2405}}

;Jimpu 2: {{cvt|130|–|165|hp|0}}{{sfn|Mikesh|Abe|1990|page=277}}

;Jimpu 3: {{cvt|150|–|180|hp|0}}{{sfn|Mikesh|Abe|1990|page=89}}

;Jimpu 6: {{cvt|130|–|160|hp|0}}{{sfn|Mikesh|Abe|1990|page=254}}

;Jimpu Kai:{{cvt|150|hp|0}}

The Jimpu 5 or Hitachi Tempu was a 9-cylinder derivative that produced between {{convert|240|and|280|hp|kW|0|abbr=on}}.{{sfn|Suzuki|et al|2008|page=2405}}{{sfn|Mikesh|Abe|1990|page=92}} The Tempu became an important engine for the company, taking 53% of production in July 1944.{{sfn|D'Olier|et al|1947|page=6}}

• Aichi AB-3 130 hp{{sfn|Mikesh|Abe|1990|page=70}}
• Aiba Tsubami IV 130 hp{{sfn|Jackson|Jackson|2000|page=113}}
• Gasuden KR-1 150 hp{{sfn|Mikesh|Abe|1990|page=89}}
• Gasuden KR-2 150 hp{{sfn|Mikesh|Abe|1990|page=89}}
• Hitachi T.2 150 hp{{sfn|Ursinus|1941|page=195}}
• Kawanishi K8K1 160 hp{{sfn|Mikesh|Abe|1990|page=141}}
• Tachikawa KKY-2 150 hp{{sfn|Mikesh|Abe|1990|page=251}}
• Tachikawa R-38 150 hp{{sfn|Mikesh|Abe|1990|page=254}}
• Watanabe K8W1 160 hp{{sfn|Mikesh|Abe|1990|page=261}}
• Yokosuka E6Y 160 hp{{sfn|Mikesh|Abe|1990|page=279}}
• Yokosuka K2Y2 130 hp {{sfn|Jackson|Jackson|2000|page=119}}
• Yokosuka K4Y1 130 hp{{sfn|Mikesh|Abe|1990|page=278}}

{{Pistonspecs

| ref = Japanese Aero-Engines 1910–1945.

| type = 7-cylinder, single row, air cooled radial engine

| bore = {{convert|115|mm|in|abbr=on}}

| stroke = {{convert|120|mm|in|abbr=on}}

| displacement = {{convert|8.37|L|in3|0|abbr=on}}

| length = {{convert|885|mm|in|abbr=on}}

| diameter = {{convert|970|mm|in|abbr=on}}

| width =

| height =

| weight = {{convert|184|kg|lb|abbr=on}}

| valvetrain =

| supercharger =

| turbocharger =

| fuelsystem =

| fueltype = 80 Octane petrol

| oilsystem =

| coolingsystem =

| power =

• Take-off: {{convert|160|hp|kW|0|abbr=on}} at 2,050 rpm at sea level
• Cruise: {{convert|130|hp|kW|0|abbr=on}} at 1,800 rpm at sea level

| specpower =

| compression =

| fuelcon =

| specfuelcon =

| oilcon =

| power/weight =

| designer =

| reduction_gear = Direct drive

| general_other =

| components_other =

| performance_other =

}}

{{aircontent

|see also=

|related=

|similar aircraft=

|lists=

• List of aircraft engines

|similar engines=

}}

{{reflist}}

• {{cite book |last1=D'Olier |first1=Franklin |last2=Nitze | first2=Paul H. |display-authors=1 |title= Hitachi Aircraft Company (Hitachi Kokuki K.k.) Corporation Report No.VII| publisher=The United States Sytrategic Bombing Survey |year=1947 |ref={{harvid|D'Olier|et al|1947}} |url=https://books.google.com/books?id=TvYsAAAAIAAJ}}
• {{cite book |last=Francillon|first=René J.|title=Japanese Aircraft of the Pacific War|year=1970|publisher=Putnam|location=London|isbn= 978-0-37000-033-6}}
• {{cite book |last1=Goodwin |first1=Mike |last2=Starkings |first2=Peter |title=Japanese Aero-Engines 1910-1945 |date=2017 |publisher=MMPBooks |location=Sandomierz, Poland|name-list-style=amp |isbn=978-83-65281-32-6}}
• {{cite book |last=Gunston |first=Bill |title=Development of Piston Aero Engines |location=Sparkford |publisher=PSL Patrick Stephens |year=2006 |isbn=978-0-75094-478-6}}
• {{cite book |last=Iguchi |first=Haruo |title=Unfinished Business: Ayukawa Yoshisuke and U.S.-Japan Relations, 1937-1953 |location=Cambridge |publisher=Harvard University Press |year=2003 |isbn=978-0-67400-374-3}}
• {{cite book |last1=Jackson |first1=Aubrey Joseph |last2=Jackson |first2=Roger T. |title= Avro Aircraft since 1908 |location=London |publisher=Putnam |year=2000 |isbn=978-0-85177-797-9}}
• {{cite book |last1=Mikesh |first1=Robert C. |first2=Shorzoe |last2=Abe |title=Japanese Aircraft 1910-1941 |location=London |publisher=Putnam |year=1990 |isbn=978-0-851-77840-2}}
• {{cite book |last=Sanger |first=Ray |title=Nieuport Aircraft of World War One |location=Marlborough |publisher=Crowood Press |year=2002 |isbn=978-1-86126-447-3}}
• {{cite journal |last1=Suzuki |first1=Takeshi |last2=Kaki|first2=Kenichi |last3=Takahashi |first3=Toyohiro |last4=Nakanishi |first4=Masayoshi |display-authors=1 |title=「ハ51型 」星型22シ リンダエンジンとガス電航空エンジンの系譜 |trans-title=The Radial 22 Cylinder Engine "HA51" and Genealogic Survey of the Gas-Den Aero-Engine |journal=Transactions of the Japan Society of Mechanical Engineers C |volume=74 |number=746 |pages=2403–2410 |language=Japanese |year=2008 |doi=10.1299/kikaic.74.2403 |ref={{harvid|Suzuki|et al|2008}}|doi-access=free }}
• {{cite journal |last=Ursinus |first=Oskar |title=Jap. Hitachi T-2 Schulfugzeug |journal=Flugsport|volume=33|number=10|year=1941|pages=195–196|language=German}}
• {{cite book |last=Wilkinson |first=Paul Howard |title=Aircraft Engines of the World |publisher=Paul H. Wilkinson |place=New York|year=1945 |url=https://archive.org/details/in.ernet.dli.2015.205335}}

{{Hitachi aeroengines}}

Category:1920s aircraft piston engines

Category:Aircraft air-cooled radial piston engines

Category:Hitachi aircraft engines